Is a Cloud-Based IP-PBX Right for You?
PBXs (Private Branch Exchange) make connections among the internal telephones of a private organization—usually a business—and also connect them to the public switched telephone network (PSTN) via trunk lines. The trunk lines can be analog PSTN lines, PRI (Primary Rate Interface) channels over T1 or, in the case of IP-PBXs, the more modern VoIP-based SIP trunks can be used in conjunction with analog and PRI trunks.
Similar to other cloud-based services, now you can get your IP-PBX functionality through a cloud service, either via a third-party, cloud-based PBX service provider, or by deploying your own PBX solution in a private or public cloud. Let’s take a look at the advantages of having the PBX in the cloud vs in your office location with respect to various factors.
Reliability & Voice Quality: Since these are the most important factors for phone calls, let’s look at these two factors first. If the IP-PBX is located at the office location, your phone answering system is dependent on the availability of your office. Since your office will be more vulnerable than a professional data center, the reliability advantage point goes to the hosted PBX. As an example, your PBX can still forward calls to extensions (say mobile phones) even if the power at the office is down.
With a cloud-based PBX, you have to rely on VoIP-based SIP trunks as it is not as practical, or sometimes not feasible, to have analog T1-based voice trunks at a data center. However, the connectivity at the data center is going to provide an excellent transport for your VoIP packets. The critical component therefore is the last mile, i.e. your WAN connectivity from the office to the data center that is hosting the PBX. If you are relying on a single MPLS connection or a single broadband connection, your office phones are only as good as your WAN link. Without a Broadband Bonding (WAN Virtualization, packet-level load balancing) type approach, the voice quality and reliability can suffer with a cloud-based PBX. Once you have a Broadband Bonding appliance that can dynamically leverage more than one broadband connection, your voice quality and reliability will be top notch.
Flexibility & Scalability: There is no question that the cloud-based IP-PBX will have the most scalable and flexible architecture, especially in multi-office environments. A prime example for IT consolidation, PBX is one of the services that will largely benefit from centralized management and maintenance, as opposed to having individual and separate PBXs per office. In essence, the cloud-based PBX approach can leverage all the benefits of the virtualization technologies including server virtualization and WAN virtualization. A Broadband Bonding appliance, for example, can keep the phone call alive even though one of the broadband lines at the office goes down during the call (session continuity with auto failover). The packet-level load balancer will adaptively recover and therefore shield the outage from the SIP layer, as long as one of the WAN links at the office is up and running.
Overall verdict? If designed correctly, the cloud-based approach wins again.
Cahit Akin, CEO, Mushroom Networks, Inc.
Mushroom Networks is the provider of SD-WAN (Software Defined WAN) and NFV solutions capable of Broadband Bonding that enables self-healing WAN networks that route around network problems such as latency, jitter and packet loss.